Door lift mechanism



De- 3l, 1940- J. J. oLEKslw DOOR LIFT MECHANISM Filed 'June 1o, i939 ATTO R N E'Y Patented Dec. 31, 1940 UNITED* STATES PATENT ,OFFICE Application June 10, 1939, Serial No. 278,439

8 Claims.

This invention relates vtolift mechanism in general and in particular to such mechanism when applied to sliding doors intended for railway service.

A large number of 'distinct types of door lift mechanisms are at present in use butin practically every case these mechanisms are hard to operate due to sliding or rubbing contact between the lift parts. It is an object, therefore, of the present invention to provide a door'lift mechanism with the parts soarranged as to reduce the frictional drag to a minimum during the lifting of the door.

A further object of the invention is the provision of a door lift mechanism having the main door supporting rollers carrieddirectly by the door and in spaced relation to Vthe supporting track at all times.

A still further object of the 'invention is the provision of a door lift mechanism in which the main door supporting rollers` are carried directly by the door for rotational movement only, thereby permitting of the proper and permanent alignment of the bearings.

These and other objects of the invention will be apparent to persons skilled in the art from a study of the following description and accompanying drawing in which:

Figure 1 is a partial side view ofthe improved mechanism with parts broken` away to better disclose the construction; i

Fig. 2 is a transverse sectional the lower portion of the door;

Fig. 3 is a side view similar to Figure 1 but showing the parts in door lifted position, and

Fig. 4 is a sectional view taken substantially on line 4--4 of Fig. 3.

Referring now to the drawing in detail, it will be seen that the front and rear door stiles V2 are connected together adjacent their lower ends by inverted box section ybottom rail 4 which is also connected to the door panel 6. The bottom rail, as previously mentioned, is of general inverted box section having sides 8 connected together at the top by web or -cover I0 and formed at the bottom with inner and outer flanges I2 and I4 respectively adapted to overlap the supporting track T. Normally, the edges of the bottom rail rest upon the track as shown in Figure 1 and prevent any sliding movement of the door upon the track.

Main door supporting rollers I6 are carried within the bottom rail adjacent each end thereof and are mounted upon axles I8 supported by the sides of the bottom rail, either by being view through projected therethrough or resting in bearing lugs attached to thesides. In this manner it will be seen that the main door supporting rollers may be carefully aligned in the bottom rail and the axles properly located soi as to .reduce the friction to a minimum and maintain the bearings in perfect alignment. 'Since the main supporting rollers may have only rotational movement and since their connection with the door rotatably carried by an axle 22 extending into side pieces 24 constituting what may be vtermed a cage for the lift'rollers. The side arms ofthe cage for the fforward lift rollers are connected by pin 26 to casting or 'forging 28 pinnedfor otherwise non-rotatably connectedV to' shaftv 3U journaled in the bottom rail and extending up# Wardly for connection with a handle `32. The casting orforging 28 is formed with spaced arms, between V'which is positioned one end of connecting' bar 36 and through'which 'the pin 26 extends to connect the bar to the casting. `The opposite end of the connecting bar is secured by any suitable means, such as rivetsf38, to the spaced arms of the'r'e'ar lift roller "cage, "I'he door operating handle is preferablyjformed integral with the shaft 30 and is provided withinwardly extending lugsy III) and 42, forming a handgrip portion which will prevent'slippage of the operators hand while at the same time protecting the hand from injury by contact with the door. It will be obvious that the lift rollers may be journaled on their axles or the axles may be journaled inthe cage sides, in which case it wouldbe more economical to form the axles drectly on theA rollers. y f Normally, the door is in vposition as vshown in` Figure 1, in which case the door rests directly on the track and the lift rollers 28 do not support any portion of the load. In fact, -it will be seen from the angular relation of the parts and the fact that the handle may rotate that it would be impossible for the rollers to assume any load, therefore, the bearings cannot be injured during transit. When it is desired to lift the door it is only necessary to rotate the operating handle downwardly to approximately 45, forcing the cages toward the side-edges of the door, thus causing the lift rollers 20 to roll along the track and along and over the surface of the main supporting rollers I6. Since the main load is carried bythe lift rollers and supporting rollers, it will be by limiting the amount of movement permitted one of the cage members, such as the forward one, by use of a stop 50, the thickness' of whic may be preselected. I y f While the invention has been described more or less in detail, it is obvious that various modications and rearrangements of parts other than `those shownv and referred to" may be made by persons skilled in thea'rtand all such`modifications and'rearrangements of parts are contemplated aswill fall within the scope of the appended claims which den'e my invention.

What is claimed is:

1. In a lift device for sliding doors having a bottom portion normally'resting on a supporting track, the combination of main door vsupporting rollers journaled on' said door with their peripheries held in spaced relation to said track at all times, and door lift rollers shiitable into the space between and into vdirect Contact with said main rollers and trackto lift the door.

2.]In a lift devicel for sliding doors having a bottom portion normally resting on a supporting track, the combination of main door supporting rollers journaled on said door with their peripheries held in spaced relation tovsaid track at all timesdanddoor lift rollers shiftable into the space between said main rollersand track to lift thek door, said main rollers rolling jupon the door lift rollers during'sliding ofr the door'.

3. In" a, liftdevilcepfor sliding doors having `a bottomv portion normally resting on a supporting track, thecombination of main door supporting rollers journaled on 'said door with their peripheries heldin spaced relation to said' track at all.times, door lift rollers 'shiftable into the space betweenand into',` direct contact with said main, rollers and track to lift the door, and means connected to said lift rollers to force the same into saidspace and retain the same therein during sliding of thedoor.v V

4. In a lift device for sliding Vdoors having a bottom portion normally resting on a supporting track, the combination of main door supporting rollers journaled on said door with. their peripheries held in spaced relation to said track at It should be noted that the force necessary to retain the parts in the position A. 'shown in Fig. 3 may be rather nicely regulated al1 times, an operating handle, cages connected to said handle, and door lift rollers journaled in said cages, said operating handle shifting the cages to force said, door lift rollers into the space between and into direct contact with the main supporting rollers and track for joint rotary motion during sliding of the door.

. 5. In a lift device for doors slidable along a supporting track and having a bottom rail, a main anti-friction 'door supporting device mounted in said bottom rail with its lower-most por- `tlon spaced from the track, and an anti-friction door lift device shiftable into the space between said rst named device and track to lift thejdoor'vertically relative to said track, said anti-friction devices together supporting the door vin liftedpo'sition and rotating in unison during sliding of the door.v

6. In a lift device for doors slidable along a supporting track and having a bottom rail, a main anti-friction door supporting device mounted in said Vbottom rail Ywith its lower-most portion spaced fromv the track, andan anti-friction door lift device shiftable into the space between said first named device and track to lift the door vertically relative to said track, said second named device rolling vupon said track and rst named device during shifting of the device relative to the door and also during sliding of the door.

7.In a lift device for doors slidable alonga supporting track and having a bottom rail, a main anti-friction door supporting devicemounted in said bottom'rail with its lower-most portion spaced from the track, a cage carried within said bottom rail,means to shift said cage withlin said rail, 'and' an anti-friction door lift device mounted in said cage and rolling on said rst named device and into the space between said rst named device and track during shifting ofthe cage .to lift the door vertically relative to said track, said door lift device also rolling upon said'jmain anti-friction door supporting device and track during sliding ofthe door.

8. In a lift device for doors slidable along a supporting track and having a bottom rail, main anti-friction doorr supporting devices mounted in said bottom, rail adjacent each end thereof and with their lower-most portionsspaced from the track,v an operating/handle carried by the rail, cages adjacent each anti-friction device and connected to said/handle and movable therewith, and an anti-friction door lift device mounted in each cage, said last nameddevice being movable with said cage and rolling. into the space between and in contact with the rst-named device and` track to lift the door vertically relative to the track, said devices rolling upon each other to anti-frictionally support the door in lifted position duringlsliding movement of the door.

\ JEROME J. OLEKSIW. 

